Removal of Organic and Inorganic Salts from Hydrocarbon Contaminated Water using Activated Carbon Materials from Agricultural Residues

In the oil and gas industry, approximately 250 million barrels of water are produced daily worldwide, a number that may increase as producing fields decline and new methods are developed to improve hydrocarbon extraction. Due to the large volumes of water reaching the surface, there is a need to develop new treatment and reuse techniques. To address this need, many industries have shown increasing interest in using adsorbent materials. This study explores how effectively activated carbon can remove common organic and inorganic salts from polluted water, including substances like methylene blue, potassium dichromate, and silver. The adsorbent materials were created by thermally treating residual plant biomass from palm kernels, cocoa husks, and sugarcane bagasse. The activated carbons were produced through a chemical activation process using phosphoric acid (H3PO4), followed by heating at 430°C. Experiments took place in a tubular reactor with a steady flow of nitrogen gas at 50 mL/min. These materials were analyzed using Fourier transform infrared spectroscopy (FTIR-ATR) and BET surface area analysis with the Brunauer-Emmett-Teller method. The surface areas of activated carbons derived from palm kernels, cocoa husks, and sugarcane were approximately 890, 970, and 215 m²/g, respectively. Furthermore, the activated carbon from palm kernels showed the highest effectiveness in removing methylene blue, potassium dichromate, and silver sulfate, achieving average removal rates of 99.6%, 92.6%, and 57.7%. Finally. The adsorption model that best fit the results was the Freundlich model, confirming the kinetic behavior. Overall, activated carbons produced from residual plant biomass are seen as a good alternative to improve the removal of contaminants from polluted water produced by the oil & gas industry.